Hyrynsalmi is a municipality in Finland and is part of the Kainuu region.
The municipality has a population of 2,465 (30 June 2015) and covers an area of 1,521.36 square kilometres (587.40sqmi) of which 100.32km (38.73sqmi) is water. The population density is 1.73 inhabitants per square kilometre (4.5/sqmi).